The Winchester Model 1910 Self-Loading rifle in .401 WSL with 20-inch barrel was the most powerful of Winchester's early semi-auto centerfire series. The .401 WSL cartridge was essentially a large-bore pistol round in rifle configuration, designed for close-range deer and black bear hunting. A pre-WWI semi-auto hunting rifle of significant historical importance. Type: Semi-Auto Rifle Action: Blowback Caliber: .401 WSL Capacity: 4 Year introduced: 1910, USA Weight: 7.5 oz Overall length: 39.5" Status: Discontinued Intended use: Hunting